Wireless telegraphy.



No. 700,250. Patented May 20, I902.

H. SHOEMAKER. WIRELESS TELEGRAPHY.

Application filed July 81, 1901.)

(No Model.) 7 v o; 2 Sheets-Sheet l.

N k U 140 700350.; I Patented May 20,1902.

H. SHOEMAKEB. WIRELESS TELEGRAPHY.

[Application filed July 31, v1901.) (No Model.) t 2 Sheets-Sheat 2.

UNITED STATES PATENT O FI E.

HARRY SHOEMAKER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GUSTAVE P. GEHRING AND AMERICAN \VIRELESS TELEPHONE AND TELEGRAPH COMPANY, OF PHILADELPHIA, PENNSYLVANIA.

srncrnxcnrroiv forming atti was Patent ta -toga; braked May 20, 1902.

Application filed July 31.

To all whom-itvvtay concern: 7

Be it known thatI, HARRY SHOEMAKER, a citizen of the United States, residing'at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements inwir'el'ess Telegraphy, of which'the following is a specification. w 1

This invention relates .to improvements in wireless telegraphy; and the main object is to provide a device by which the coherer is absolutely protected from the action of the spark-coil at the same station, as I provide a single aerial wire, to which is connected a transmitting apparatus and a receiving appa-V 'ratusthat is, by means of a switch I can connect the transmitting apparatusa'nd disconnect the receiving apparatus,or vice versa,and thus in all cases keep the apparatus under complete control by a very simple operation, the practice before now being the' employment of a tin or metal box. With this device the operation of the wireless system is similar to the wire system, as a switchjmust be used to receive and send and m ust be operated by the operator. Another important point in this apparatus is the fact. that it is impossible to transmit a spark or awaveluntil the receiving apparatus; has been fully protected. To attain this end, I have illustrated in the accompanying drawings an apparatus setting forth my invention, and in which- Figure 1 is a diagrammatical view of one terminal of the system, a transmitting and receiving station being fully disclosed therein. Fig. 2 is a sectional view of a device for making direct connections with the receiving or transmitting apparatus, and Fig. 3 is an enlarged detail view'of the switch 'andits connections for connecting or disconnecting the proper apparatus of the terminal.

Referringto' the drawings, 'A designates a transmitting-station, and B the receiving-staion.

The air-plate l is provided with the conductor-wire 2, which is connected to the lever 3. This lever'is'provided with the arm 4, to which is connected the spring 5. Connecting this lever with a similar lever 6 is the insulating- Serial No. 70,359 (No model 1 rod 7, whichallowsthese levers to be operated'in'unis'on by means of the spring 5 or the rod 8, connected tothe core 9 of the solenoid 10. Adapted to be connected by the lower end of the lever 3 is acontact 11, to which is connectedthe wire;12,;connected to the sparkcoil 13, a'wire 14 connecting the coil with the ground 15. Connected with the coil 13 isjthe wire 16, batteries 17, wire 18, contact 19, pivoted lever 20, which, with the lever 21, connected by the insulating strip or bar 22, constitute my switching device. A wire 23 is connected to the pivot-point of the lever 20 and also the transmitting-key 24. This key is connected through the vibrator 25 to the spark- .coil, a condenser 26 spanning or bridging the gap. This virtually covers the entire transmitting apparatus.

The receiving apparatus consists, substantially," of the lever 6, whose upper end is connected with the ground 27 by means of the wire 28 and the wire 28*, its lower end being adapted to contact the point 29, to which is connected 2. wire'30, which is connected to ground 27 by means of the switch-points 31, wire" 32, imperfect electrical contact or co- .herer 33, wir'e 34, switch-points 35, and wire 36.

The switch-points 31 and 35, respectively, are insulated from the armatures 37 and 38,-re-

spectively, by means of the insulating-blocks 39. These armatures are operated by the magnets 40 and 41, which are adapted to open and close the circuit from point 29 to the ground on each side of the coherer. This would leave the coherer without any circuit except the relay-circuit 42, which has so much inductance 43 that no oscillation will be set up therein when its circuit is open at 31 and 35. The solenoid 10 has its circuit-. througho vire 44, switch 21, wire-I45, battery 46,-wire 47,

magnet ethawire 48,,magnet340,.andwit-e49.'

When 20 is closed, the primary otitheinduc tion-coil is put inreadinessfor use; and a current is made through magnets 40, 41, and 10 and puts the apparatus in the position that is shown in Fig. l -that is, it insulates the coherer and connects the transmitter in circuit. When. the receiver is in action, the switchis open, and this connects lever 3 to point 29, and this disconnects lever 6 from 29, this action being caused by the spring 5. At this instant the gaps at 31 and 35 are closed, and the coherer is placed in a condition to receive the oscillation. l/Vhen the transmitter is in use, the lever 6 contacts 29, at which time the electromagnets 40 and 41 are energized andby overcoming the tractile springs attract the armatures 37 and 38, and thus cut the coherer from connection with the wires 30 and 28, thus insuring against any damage to the coherer. The wire 28 at this point should any disturbance or wave eitect the lever 6 will cause said wave to be conducted through the wire 28 to the ground 27, thus doubly insuring the coherer.

In Fig. 2 of the drawings I have illustrated, on an enlarged scale, a casing 51, which is provided with an opening 52,iu which is adapted to swing the lever 3, pivoted and supported by the standards 53, and to a bracket or lug 5 L is pivoted the lever 6, said lever being located in the casin To the standard 53 and also the casing 5a are connected the bindingposts and 56, respectively, to which are connected the wires 2 and 28, respectively. The point 29, which is also located in the easing, is provided with the binding-post 57, to which a wire 30 is connected, and the point 11 is provided with the long arm 58, to whose outer end is connected the binding-post 59, to which is connected the wire 12. Mounted upon the casing is the solenoid 10, provided with the plunger 9, which operates the lever 3 through the mediumof the rod 8.

From this description, taken in connection with the drawings, the operation of the system is very readily understood, and when it is desired to usethe transmitting apparatus it is simply necessary to cause the lever 20 of the switch device to connect to contact 19 and complete the spark-coil circuit. This at the same time causes the lever 21 to contact the point- 21", thus causing the magnets 40 and 4E1 to operate their armatures 37 and 38, and thus cut the coherer out of the circuit. By manipulating the transmitting-key 24: the sparkcoil is set in operation and oscillations are produced which are received by the'receiving apparatus at the other terminal. By breaking the connections at 19 and 21, respectively, the solenoid 10 is deenergized, allowing the spring 5 to cause the lever 3 to contact the point 29. The magnets 40 and 41 having also become demagnetized allow the springs 50 to operate the switches 31 and 35, and thus place the coherer in operative condition to receive the impulses sent by the transmitting apparatus at the other terminal.

The object of the electromagnetically-operated and spring-returned switch is for the pn rpose of automatically connecting or disconnecting the proper instrument with the conducting-wire 2. It is placed upon a wall or properly-insulated place, and being of a high potential it would be very inconvenient for the operator to leave his transmitter or receiver every time he wishes to change from one instrument to the other, so the small hand-switch is placed near the instruments different ground connections and are provided with an intermediate switching device which connects the transmitting apparatus and the receiving apparatus one at a time with the aerial conductor.

That I claim as new, and desire to secure by Letters Patent, is

1. In a Wireless-telegraph system, the 001m bination in a terminal station, of an aerial conductor, a transmitting instrument, a receiving instrument, an electromagueticallyoperated and spring-retiu'ned means connected to the conductor, and a switch to make a circuit, which energizes the said means to connect the transmitting instrument to the aerial conductor, the spring at other times causing the receiving instrument to be connected to the aerial conductor.

2. A terminal station of a wireless-tele graph system,comprisin g an aerial conductor, a pair of levers insulated from each other and adapted to swing in unison one being 0011-.

nected to said conductor, means for operating said levers, a transmitting apparatus, a receiving apparatus, and a switch for controlling a circuit to operate said levers to connect the transmitting or the receiving apparatus with the aerial conductor.

3. A terminal station of a wireless-telegraph system comprising an aerial conductor, two independent insulated means adapted to move in unison and having one connected with its aerial conductor, a transmitting ap paratus, a receiving apparatus, and means for controlling a circuit to operate said before-mentioned means to connect the transmitting or the receiving apparatus with the aerial conductor.

4:. A terminal stationof a wireless-telegraph system comprising an aerial conductor, a pair of levers insulated from each other and adapted to swing in unison, one of said levers with the solenoid for cutting the receivingstation out when the transmitting-station is being operated.

- ed with the aerial conductor to cut the receiving instrument out.

7. A terminal station for a wireless-telegraph system comprising an aerial conductor, a transmitting apparatus, a receiving apparatus having a coherer, a relay-circuit and a sounder-circuit,electromagnetically-operated means for connecting the aerial conductor with the transmitting or receiving apparatus,

another electromagnetically-operated means in the same circuit as the one above men- I tioned energized when the transmitting appaand two ground-conductors, atransmitting apparatus, a receivingapparatus, a pair of levers for connecting the transmitting appa= ratus or the receiving apparatus to the aerial conductor, a circuit made when the transmit ting apparatus is connected to the aerial con ductor, and electromagnetically operated means for cutting out the receiving appara tus when the transmitting apparatus is connected with the aerial conductor.

9. A terminal station of a wirelesstele graph system comprising an aerial conductor, a transmitting apparatus, a receiving appa ratus, a pair of pivoted levers adapted to be operated to connect the transmitting or receiving apparatus to the aerial conductor, a circuit, a solenoid and a pair of electromagnets located in said circuit, a switch for connecting said circuit to energize thesolenoid to'operate the levers and connect the transmitting apparatus with the aerial conductor, and switch-points operated simultaneously by the electromagnets to cut out the receiv* ing apparatus,

In testimony whereof I affix my signature in presence of two witnesses. I

HARRY SHOEMAKER.

Witnesses:

J. N. FORT, Jr., CHAs. J. FoREMAN. 

